Adam Ludwin recently launched a social photo album app called Albumatic. Before its launch, he showed the app to a focus group of 20+ people under the age of 25. Most told Ludwin they didn't like how reliant the app was on Facebook.

His test group doesn't seem to be an outlier. Branch CEO Josh Miller recently asked his 15-year-old sister if she still used Facebook in a blog post titled "10th Grade Tech Trends." According to his high school sibling, teens are obsessed with Instagram and Snapchat, but they're less enthralled with Facebook.

"She mentioned that she tries to visit Facebook as infrequently as possible," he wrote. She also told Miller she only visits Facebook after she's thoroughly stalked people on Instagram.

Even Facebook Chat isn't as appealing as it once was. "When you go on Facebook Chat the people you don’t want to talk to are always the ones who immediately chat with you,” his sister said.

We believe that some of our users, particularly our younger users, are aware of and actively engaging with other products and services similar to, or as a substitute for, Facebook. For example, we believe that some of our users have reduced their engagement with Facebook in favor of increased engagement with other products and services such as Instagram. In the event that our users increasingly engage with other products and services, we may experience a decline in user engagement and our business could be harmed.

Why isn't Facebook "cool" anymore? The Verge's Ellis Hamburger asked a few social media experts for their thoughts.

"I think it has less to do with kids consciously looking for 'the next big thing' than Facebook just no longer being a space that serves them," one said. In other words, it used to be "cool" to brag about yourself and show pictures to friends on Facebook. Now people are looking for more intimate places to share items with a handful of people, like Snapchat. There's a sense of privacy there, and it meets a need Facebook has grown too big to serve.

Of course, this doesn't mean teens are deleting their Facebook profiles. They're just looking to use the service less, and they're open to communicating on other platforms.

The good news for Facebook is that teens are still rabid Instagram users. So while they may be shifting attention away from the social network, Zuckerberg can still monetize them on mobile devices.